Context: Malaria accounts for 1-3 million deaths yearly worldwide, mostly in children under 5 years of age in sub-Saharan Africa. Laboratory and clinical studies show an association between acute malaria and a decreased response to diphtheria and tetanus toxoids and to meningococcal, salmonella, and Haemophilus influenzae type b vaccinations. Malaria treatment, chemoprophylaxis, or other forms of parasite suppression might improve the immune response to childhood vaccinations. However, the antimalarial 4-aminoquinolones are immunodepressive, such that antimalarial drugs might depress the vaccine response.
Starting point: Last year, Julius Massaga and colleagues reported a randomised double-blinded placebo-controlled study in 291 infants aged 12-16 weeks in Tanzania (Lancet 2003; 361: 1853-60). At enrollment, children received their third dose of combined diphtheria-tetanus-pertussis and poliomyelitis expanded vaccines with the first of three daily doses of amodiaquine intermittent preventive treatment (IPTi) or placebo. After 60 days, children receiving amodiaquine had significantly fewer malaria fevers than controls.
Where next: The increasing concordance of malaria control and vaccination, movement toward co-administration of IPTi with immunisation, and the increase in travellers to malarious areas who receive concurrent vaccinations and chemoprophylaxis warrant further study.